Insulation displacement connectors (IDC) are well known in the art for forming connections between an insulated wire and any manner of electronic component. These connectors are typically available as sockets, plugs, and shrouded headers in a vast range of sizes, pitches, and plating options. A common feature of IDCs is one or more contact elements incorporating a set of blades or jaws that cut through the insulation around the wire and make electrical contact with the conductive core in a one-step process, thus eliminating the need for wire stripping and crimping, or other wire preparation. IDCs are used extensively in the telecommunications industry, and are becoming more widely used in printed circuit board (PCB) applications.
U.S. Pat. No. 6,050,845 describes an IDC assembly that can be mounted and secured to a circuit board prior to terminating conductors to the connector. The electrical connector includes a housing having at least one conductor-receiving aperture and an associated terminal-receiving passageway extending from a board mounting face and intersecting each conductor-receiving aperture. A terminal is disposed in each terminal-receiving passageway and includes a body portion having a first connecting section extending from one end and adapted to be inserted in a through-hole of a circuit board, and a pair of upstanding arms defining an IDC slot for receipt of a wire. Each terminal is partially inserted into the housing in a first position such that a portion of the terminal body and the first connecting section extends below the board mounting face of the housing. Upon positioning the first connecting sections in corresponding through-holes of a circuit board, the terminals can be secured to the board, after which ends of insulated conductors can be inserted into respective conductor-receiving apertures and terminated therein to respective terminals by moving the housing toward the board to a second position against the board and simultaneously pushing all the corresponding wires into respective IDC slots.
Attempts have been made to configure IDCs for surface mounting technology (SMT) applications as well. For example, U.S. Pat. No. 7,320,616 describes an IDC specifically configured for SMT mounting to a PCB. The connector assembly has at least one contact member with a piercing, cutting or slicing end that is slideably disposed within a main body, and a mounting end that extends from the main body and is attached to a printed circuit board using conventional SMT processes. An insulated conductor, such as a wire, cable and/or ribbon, is inserted in a channel in the main body without being pierced by the piercing end of the contact. When a user pushes down on the top portion of the main body, the contact slides into the channel and pierces the insulated conductor. The top portion of the main body also provides a surface for a vacuum pick-up nozzle in an automated pick-and-place assembly process.
The IDCs in the above cited references are relatively complicated in that they require all or a portion of the main body to be movable or slidable relative to the contacts to make final connection with the wires after ends of the contacts have been inserted into through holes in the PCB or surface mounted to the PCB. In addition, a perception to some in the industry is that IDCs are not well suited for stressful environments wherein the electrical component is subjected to prolonged shock and vibrations because the wires tend to move or pull out of the contact blades.
AVX Corporation having a principal place of business at Fountain Inn, S.C., USA, provides a discrete wire-to-board IDC (Series 9175/9176/9177) that has provided significant benefits and advantages to IDC applications. This connector is available in various pin configurations and is SMT assembled to a PCB prior to assembly of the wires. A small application hand tool is used to insert the wires into the respective contact slots. This process cuts the insulation and enables the individual wire conductors to form a homogeneous joint. U.S. Pat. No. 7,976,334 describes a further improvement that is particularly suited for (but not limited to) the AVX Series 9175/9176/9177 connectors discussed above. The connector assembly of the '334 patent includes one or more contact elements stationarily fixed in an insulator body, with opposed blades or jaws of the contact elements aligned with channels in the body. A cap is configured to engage over the body and includes recesses with an open bottom that align with the body channels. The cap serves the function of a tool for inserting wires into the contact elements, for example between the opposed blades or jaws of the elements. The cap may also serve the optional feature of covering and protecting the contacts, and to prevent inadvertent removal or pulling out of the wires from the contact elements. The cap may also serve to cover and protect the open ends of live wires inserted in the connector assembly. Although a significant advancement in the art, this connector assembly according to the '334 patent requires two separate insulator material moldings, namely the body and the cap, which adds to the overall cost of the connector assembly.
A welcome improvement in the art would be a connector assembly that incorporates the benefits of the '334 patent discussed above without the complication and expense of separate moldings.